1. Field of the Invention
This invention relates to a valve assembly for filling gas cylinders, more particularly a valve assembly that reduces the amount of gas wasted during the filling process.
2. Prior Art
During tank filling processes when toxic or hazardous chemicals are being transferred into smaller cylinders, chemical loss occurs when the cylinders are connected to and disconnected from the manifold because the chemical sometimes remains in the lines that connect the manifold and the cylinders and leaks to the environment. This chemical loss is a health risk to both the operator and to the surrounding areas. Thus, a need exists for a valve connection that can minimize this chemical loss.
Several devices have been developed in the past, but none of these devices efficiently meets these concerns. An example of a prior art device is shown in U.S. Pat. No. 5,379,793. A need exists for an improved valve assembly that can decrease chemical loss every time a tank is filled while at the same time increasing the safety of the operators.